Illustrating the roles of C-reactive protein in the development of the metabolic syndrome in women--a cross-racial validation

Metabolic syndrome and weight status may modify the inverse association between handgrip strength and C-reactive protein in Korean adults

Metabolic and weight phenotype-specific relationships between high-sensitivity C-reactive protein (hsCRP) and handgrip strength (HGS) may compare the phenotypes that can potentially influence association between HGS and hsCRP risk. However, these phenotype-related differences remain unclear. The present study investigated the associations between HGS assessed using raw HGS of each hand and relative HGS (HGS/body mass index [BMI]) and hsCRP status according to metabolic and weight phenotypes. In 15 061 Korean adults (50.8 ± 16.6 years) with complete data from the Korea National Health and Nutrition Examination Survey from 2015 to 2017, hsCRP levels were classified into high risk (>3 mg/L) vs low to average risk. Metabolic and weight phenotypes were categorized into 6 groups according to the number of metabolic syndrome (MetS) components (0/1-2/3-4) and the absence/presence of obesity (BMI ≥ 25 kg/m²). After adjusting for confounding factors (demographics, treatment of concurrent illnesses, and health-related behaviors), high-risk hsCRP had inverse associations with HGS values, whereas it had positive associations with phenotypes having higher number of MetS components and higher BMI in both sexes. In both men and women, increases of all HGS were not associated with high-risk hsCRP in the nonobese phenotype without MetS components after adjusting for confounding factors. However, those increases in HGS had inverse associations with high-risk hsCRP in either men or women with at least 1 MetS component, regardless of coexistent weight status, and those with obesity, regardless of coexistent MetS components. In conclusion, strong HGS may be more favorable for individuals with high-risk hsCRP when they have obesity or metabolically unhealthy phenotypes.

25-hydroxyvitamin D is associated with adiposity and cardiometabolic risk factors in a predominantly vitamin D-deficient and overweight/obese but otherwise healthy cohort

Vitamin D deficiency has reached epidemic proportions worldwide and has recently been linked to cardiometabolic risk factors including obesity, insulin resistance, hypertension, dyslipidemia, as well as type 2 diabetes and cardiovascular disease. The objective of this study was to examine the associations between circulating 25-hydrovitamin D (25(OH)D) levels and cardiometabolic risk factors using direct measures of adiposity, glucose intolerance, and insulin resistance, as well as lipids, blood pressure, and plasma markers of inflammation. We measured circulating 25(OH)D, physical activity (International Physical Activity Questionnaire- IPAQ), anthropometry (body mass index (BMI), waist-to-hip ratio (WHR), % body fat (dual energy X-ray absorptiometry)), metabolic parameters (fasting and 2-h plasma glucose levels during oral glucose tolerance test; insulin sensitivity (M, hyperinsulinaemic-euglycaemic clamp), and cardiovascular and inflammatory profiles (blood pressure (BP), pulse pressure (PP), mean arterial pressure (MAP), plasma lipid levels, white blood cell count (WBC), and plasma high-sensitivity C-reactive protein levels (hsCRP)) in 111 healthy, non-diabetic adults (66 males/45 females; age 31.1±9.2years; % body fat 36.0±10.2%). Mean 25(OH)D was 39.8±19.8 nmol/L with no difference between genders (p=0.4). On univariate analysis, 25(OH)D was associated with% body fat (r=-0.27; p=0.005), 2-h glucose (r=-0.21; p=0.03), PP (r=0.26; p=0.006), and insulin sensitivity (r=0.20, p=0.04), but not with age, BMI, WHR, fasting glucose, BP, MAP, lipids, or inflammatory markers (all p>0.05). After adjusting for age and sex, 25(OH)D remained associated with% body fat (β=-0.12%; p=0.003), 2-h glucose (β=-0.13mmol/L; p=0.02), PP (β=0.12mmHg; p=0.009), and insulin sensitivity (β=0.22mg/kg/min; p=0.03), and became associated with fasting glucose (β=-0.04mmol/L; p=0.04) and hsCRP (β=-0.51mg/L; p=0.04). After adjusting for age, sex, and % body fat, 25(OH)D was no longer associated with insulin sensitivity, 2-h glucose, or hsCRP, but remained associated with fasting glucose (β=-0.05mmol/L; p=0.03) and PP (β=0.10mmHg; p=0.03). 25(OH)D remained associated with fasting glucose (β=-0.06mmol/L; p=0.02) after hsCRP and physical activity were added to the model with % body fat, age, and sex. ​These cross-sectional data suggest that associations between vitamin D and cardiometabolic risk among healthy, non-diabetic adults are largely mediated by adiposity. Large-scale intervention and mechanistic studies are needed to further investigate whether vitamin D has an independent role in the prevention and/or management of cardiometabolic risk and disease.

The interplay between inflammation, physical activity and metabolic syndrome in a remote male geriatric community in Southern Taiwan: the Tianliao Old People (TOP) study 03

BACKGROUND

Both physical activity and inflammation are important in the pathophysiology of metabolic syndrome (MetS). Our study aim is to explore their associations in an elderly male (≥ 65 years old) cohort.

METHODS

We enrolled 309 elderly male residents (mean age: 74.4 ± 6.0 years) in a remote southern Taiwan community. The physical activity was recorded by a standard questionnaire. A high-sensitivity C-reactive protein (hsCRP) level > 3.0 mg/L indicated a high inflammatory status.

RESULTS

The total prevalence rate of MetS was 27.8% in this male geriatric cohort. Median hsCRP levels were significantly higher in the MetS group (1.60 ± 0.7 vs. 1.0 ± 0.3 mg/L, p < 0.01), and the risk of elevated hsCRP increased with escalating MetS components (p for trend < 0.001). The non-MetS group had higher amount of median weekly physical activity (183.1 ± 19.0 vs. 173.5 ± 10.6 MET-hr/week, p = 0.029), which was also higher among those with lower hsCRP levels (186.1 ± 14.1 vs. 167.8 ± 38.5 MET-hr/week, p = 0.013). Multivariate analysis showed that higher body mass index (ORs: 1.527, 95% CI: 1.319-1.768, p < 0.01) insulin (OR: 1.128, 95% CI: 1.045-1.218, p < 0.01) and physical activity (ORs: 0.997, 95% IC: 0.994-0.999, p < 0.05) were independent predictors of MetS, but not hsCRP level (p > 0.05).

CONCLUSIONS

Reduced physical activity was one major pathophysiological MetS factor in our Asian geriatric participants.

Association of serum C-peptide concentrations with cancer mortality risk in pre-diabetes or undiagnosed diabetes

Background

Known associations between diabetes and cancer could logically be attributed to hyperglycemia, hypersecretion of insulin, and/or insulin resistance. This study examined the relationship between initial glycemic biomarkers among men and women with impaired fasting glucose or undiagnosed diabetes and cancer mortality during follow up.

Methods

The cohort included subjects aged 40 years and above from the Third National Health and Nutrition Examination Survey (NHANES III) with fasted serum glucose >100 mg/dl without the aid of pharmaceutical intervention (insulin or oral hypoglycemics). Cancer mortality was obtained from the NHANES III-linked follow-up database (up to December 31, 2006). A Cox regression model was applied to test for the associations between cancer mortality and fasting serum glucose, insulin, glycosylated hemoglobin (HbA1c), C-peptide, insulin like growth factor (IGF-1), IGF binding protein 3 (IGFBP3) and estimated insulin resistance.

Results

A total of 158 and 100 cancer deaths were recorded respectively from 1,348 men and 1,161 women during the mean 134-month follow-up. After adjusting for the effect of age and smoking in women, all-cause cancer deaths (HR: 1.96 per pmol/ml, 95% CI: 1.02–3.77) and lung cancer deaths (HR: 2.65 per pmol/ml, 95% CI: 1.31–5.36) were specifically associated with serum C-peptide concentrations. Similar associations in men were not statistically significant. Serum glucose, HbA1c, IGF-1, IGFBP3 and HOMA were not independently related to long-term cancer mortality.

Conclusion

C-peptide analyses suggest a modest association with both all-cause and lung cancer mortality in women but not in men. Further studies will be required to explore the mechanisms.

Association of high-sensitivity C-reactive protein with cardiometabolic risk factors and micronutrient deficiencies in adults of Ouagadougou, Burkina Faso

Increasing evidence suggests that high-sensitivity C-reactive protein (hs-CRP) is associated with cardiometabolic risk factors (CMRF) while being also related to micronutrient deficiencies. As part of a project on the double burden of under- and overnutrition in sub-Saharan Africa, we assessed the relationship between hs-CRP and both CMRF and micronutrient deficiencies in a population-based cross-sectional study carried out in the Northern district of Ouagadougou, the capital city of Burkina Faso. We randomly selected 330 households stratified by income tertile. In each income stratum, 110 individuals aged 25-60 years and having lived in Ouagadougou for at least 6 months were randomly selected, and underwent anthropometric measurements and blood sample collection. The prevalence of high hs-CRP was 39.4 %, with no sex difference. Vitamin A-deficient subjects (12.7 %) exhibited significant risk of elevated hs-CRP (OR 2.5; P= 0.015). Serum ferritin was positively correlated with log hs-CRP (r 0.194; P= 0.002). The risk of elevated hs-CRP was significant in subjects with BMI ≥ 25 kg/m² (OR 6.9; 95 % CI 3.6, 13.3), abdominal obesity (OR 4.6; 95 % CI 2.2, 7.3) and high body fat (OR 10.2; 95 % CI 5.1, 20.3) (P< 0.001, respectively). Independent predictors of hs-CRP in linear regression models were waist circumference (β = 0.306; P= 0.018) and serum TAG (β = 0.158; P= 0.027). In this sub-Saharan population, hs-CRP was consistently associated with adiposity. Assuming that plasma hs-CRP reflects future risk of cardiovascular events, intervention which reduces CRP, or chronic and acute nutrition conditions associated with it, could be effective in preventing their occurrence particularly in sub-Saharan Africa.

The relationship among central obesity, systemic inflammation, and left ventricular diastolic dysfunction as determined by structural equation modeling

The purpose of this study was to investigate the associations among central obesity, inflammation, and left ventricular (LV) diastolic dysfunction by structural equation modeling. Echocardiographic parameters were assessed in 102 otherwise-healthy adults over age 30. The participants were classified as having LV diastolic dysfunction by echocardiographic findings including mitral inflow E/A ratio <1, deceleration time >220 cm/s, or decreased peak annular early diastolic velocity in tissue Doppler imaging or otherwise the control group. Serum C-reactive protein (CRP) and lipid profile were also measured. The homeostasis model of insulin resistance (HOMA) was calculated. Central obesity was assessed by computerized tomography (CT) at the L4 level. In a multivariate regression analysis, the relationship between visceral adipose tissue (VAT) and LV diastolic dysfunction became insignificant when CRP was introduced into the model, although CRP itself was significantly associated with LV diastolic dysfunction (odds ratio (OR): 1.32, 95% confidence interval (CI): 1.01-1.72, P = 0.04). A significant correlation was also found between VAT and CRP (r = 0.70; P < 0.001). We then performed path analysis as illustrated by the structural equation model. This proved our hypotheses that VAT might affect LV diastolic dysfunction through the effect of CRP (total fat load with inflammation (B = 1.133, P < 0.001) and that inflammation might affect LV diastolic dysfunction (B = 0.373. P < 0.001)). Using structural equation modeling, we concluded that higher amounts of VAT were associated with low-grade inflammation and this may lead to subclinical LV diastolic dysfunction in otherwise-healthy subjects.

The role of serum C-reactive protein in women with lower urinary tract symptoms

INTRODUCTION AND HYPOTHESIS

Some lower urinary tract dysfunction (LUTD) subtypes may be associated with low-grade inflammation. This study aimed to investigate the role of serum C-reactive protein (CRP) levels in women with lower urinary tract symptoms (LUTS).

METHODS

A total of 197 consecutive women with non-stress urinary incontinence (non-SUI) LUTS and 18 healthy women without LUTS (normal controls) were enrolled. LUTS include urinary storage, voiding, and post-micturition symptoms. Patients with previous bladder or urethral surgery, active urinary tract infections, or possible neurogenic lesions were excluded. Serum CRP levels were measured before any treatment was given. Patients were stratified to LUTD subgroups based on a 3-day voiding diary, uroflowmetry, and selective videourodynamic studies.

RESULTS

Median CRP levels were significantly higher in women with overactive bladder (OAB) wet (i.e., with urgency incontinence, n = 30, 0.12 mg/dl) than those in women with bladder oversensitivity (n = 68, 0.075 mg/dl, P = 0.008) and the control group (0.055 mg/dl, P = 0.032). Further analysis revealed that body mass index and maximum flow rate were two independent factors that affected CRP levels. The area under the receiver-operating characteristic curve for using CRP to predict OAB wet was 0.55, and the most predictive cutoff point for CRP was 0.15 mg/dl (sensitivity 43.5 %, specificity 72.7 %).

CONCLUSIONS

High serum CRP levels were found in women with OAB wet, and they were related to lower maximum urinary flow rates and higher body mass indices in non-SUI LUTD. However, serum CRP is not a suitable biomarker for discriminating between subtypes of non-SUI LUTD.

Association of amino-terminal pro-brain natriuretic peptide with metabolic syndrome

OBJECTIVE

This study evaluated the relationship between individual components in metabolic syndrome (MetS) and amino-terminal pro-brain natriuretic peptide (NT-proBNP).

METHODS

A screening program for MetS in 2008 in Taiwan excluded subjects aged <30 years and pregnant women. Fasting glucose, insulin level, high-sensitivity C-reactive protein (hsCRP), and NT-proBNP were assessed. A propensity-score matching process was used to select subjects with and without MetS comparable in age, gender, body height, and serum creatinine levels. A multiple regression model was used to determine the association between individual components of MetS and NT-proBNP. Finally 270 subjects with MetS and another 270 matched subjects without MetS aged ≥30 years were included.

RESULTS

The subjects with MetS had higher uric acid and hsCRP, but not NT-proBNP. Multiple regression model showed that log (NT-proBNP) was positively associated with systolic blood pressure (β=0.002 per mmHg, p=0.013), but negatively associated with body mass index (β=-0.017 per kg/m(2), p=0.018), triglyceride (β=-0.00048 per mg/dL, p=0.020) and insulin level (β=-0.005 per mU/L, p=0.005). Log (NT-proBNP) was neutral to waist circumference, fasting glucose, high-density lipoprotein cholesterol, and diastolic blood pressure.

CONCLUSION

MetS was not associated with serum NT-proBNP concentrations due to the contradictory effects of each component.

Effects of obesity, physical activity, and cardiorespiratory fitness on blood pressure, inflammation, and insulin resistance in the National Health and Nutrition Survey 1999-2002

BACKGROUND AND AIMS

This study was designed to elucidate the effects of obesity, self-reported physical activity and cardiorespiratory fitness on blood pressure, inflammation, and insulin resistance.

METHODS AND RESULTS

Data from 950 Caucasian subjects ranging in age from 19 to 49 years from the National Health and Nutrition Survey (NHANES), 1999-2002, were included to construct a population-based observational study. Cardiorespiratory fitness (VO(2) max) was predicted from a submaximal exercise stress test. Self-reported physical activity was measured by metabolic equivalent score transformed from a questionnaire. A structural equation model (SEM) was developed to examine the relationship between obesity, cardiorespiratory fitness, self-reported physical activity, and hypertension, inflammation, and insulin resistance. The model showed that obesity was positively linked to hypertension (B=0.50, P<0.001) and C-reactive protein (CRP; B=0.15, p<0.05), which in turn led to insulin resistance (B=0.44, P<0.05). Increased cardiorespiratory fitness was negatively associated with CRP (Γ=-0.23, P<0.01), but not correlated to hypertension after adjustment for potential confounding factors. No significant association was found between self-reported physical activity and hypertension, insulin resistance, and CRP.

CONCLUSION

Obesity contributes to the development of hypertension, inflammation, and insulin resistance. Improved cardiorespiratory fitness might lead to clinical and biochemical improvement in insulin resistance by reducing the inflammatory state.

Macrophage infiltrates with high levels of Toll-like receptor 4 expression in white adipose tissues of male Chinese

BACKGROUND AND AIMS

Macrophages and Toll-like receptor 4 (TLR4) are involved in the inflammatory process of adipogenesis. This study aimed to characterize macrophage infiltrates and the associated TLR4 expression in different locations of white adipose tissues (WAT) of male Chinese and determine their correlations to adipocyte hypertrophy and hyperplasia.

METHODS AND RESULTS

A total of 30 men, who were lean, overweight or with type 2 diabetes (T2D), were recruited. Their abdominal omental WAT (oWAT) and subcutaneous WAT (scWAT) were obtained. The contents of macrophages in oWAT and scWAT were quantified using anti-CD68 staining. The levels of TLR4 expression were analyzed by western blot assays and the adipocyte size was quantified, followed by linear regression analysis. Significantly higher numbers of macrophages (24.4+/-3.2 vs 6.1+/-2.9, p<0.001), associated with higher levels of TLR4 expression (0.59+/-0.19 vs 0.20+/-0.03, p<0.001), were observed in oWAT, as compared with that in scWAT. Furthermore, the levels of macrophage infiltrates and TLR4 expression in oWAT of subjects who were overweight or/and have T2D were significantly higher than that in the lean group. The average adipocyte diameters and cross-sectional areas in oWAT of subjects who were overweight were significantly greater than those in the lean group (p=0.003 and p=0.04, respectively). Importantly, the numbers of macrophage infiltrates were positively correlated to the levels of TLR4 expression, the sizes of adipocytes, the levels of body mass index and C-reactive protein, respectively.

CONCLUSION

Our data suggest that macrophage-related TLR4 expression and inflammation contribute to the development of adipocyte hypertrophy in male Chinese.

Associations between C-reactive protein and benign prostatic hyperplasia/lower urinary tract symptom outcomes in a population-based cohort

Inflammation may play a role in the development of benign prostatic hyperplasia and/or lower urinary tract symptoms (LUTS). Higher levels of C-reactive protein (CRP) may therefore be associated with the development of these outcomes. The authors examined the association of CRP levels measured in 1996 with rapid increases in prostate volume, prostate-specific antigen levels, and LUTS as well as rapid decreases in peak flow rates (through 2005) in a population-based cohort of men residing in Olmsted County, Minnesota. Men with CRP levels of > or =3.0 mg/L were more likely to have rapid increases in irritative LUTS (odds ratio (OR) = 2.14, 95% confidence interval (CI): 1.18, 3.85) and rapid decreases in peak flow rates (OR = 2.54, 95% CI: 1.09, 5.92) compared with men with CRP levels of <3.0 mg/L. CRP levels were not significantly associated with rapid increases in prostate volume, obstructive LUTS, or prostate-specific antigen levels. Associations were attenuated after adjusting for age, body mass index, hypertension, and smoking history (irritative LUTS: OR = 2.00, 95% CI: 1.04, 3.82; peak flow rate: OR = 2.45, 95% CI: 0.73, 8.25). These results suggest that rapid increases in irritative LUTS and rapid decreases in peak flow rates may be due to inflammatory processes.

Confirming a biological pathway in the metabolic syndrome--insight from the NHANES 1999-2002

The objective of this study was to examine the role of obesity in the development of the metabolic syndrome (MS). A total of 3,596 whites aged 19 years and above, who participated in the National Health and Nutrition Examination Survey (NHANES) 1999-2002, were included for analysis. Anthropometric measurements, biochemical profiles, and high-sensitivity C-reactive protein (CRP) were measured. A structural equation model (SEM) was constructed to elucidate a pathway in which obesity initiated the cascade leading to full MS. The results of SEM demonstrated that obesity was positively associated with elevated CRP level (B = 0.05, P < 0.001). This higher inflammatory state directed to insulin resistance (B = 0.32, P < 0.001), which in turn was positively associated with dyslipidemia (B = 0.06, P < 0.001). Obesity could also directly and positively affect blood pressure (B = 0.51, P < 0.001), without the mediation of insulin resistance and/or inflammation. The results of the cross-sectional analysis in the white subjects have shown that obesity has a strong influence on hypertension that obtains little additional influence from inflammation or insulin resistance. The metabolic profile in the NHANES group has been confirmatory with the statement that there is a sequential effect from obesity to inflammation, insulin resistance, and dyslipidemia. This approach has allowed to inferring important biological insights about the nature of the relationships among the components of MS.